I know a retired guy with a backhoe whose sole business is running around Arizona and digging graves for horses.
As far as my own dead cat and dog, our vet sends them to a pet cemetery a few miles away that does the cremation, and they let you pick whether you want the mass or individual cremation if you want the ashes. As a funny/horrible aside, the biggest fight I ever got in was when the cat died. We were on our way out the door to catch an international flight for a cruise, and that is (of course) when we found the cat dead. My wife was hysterical about what to do with the body, to which I said “Well, it IS trash day…”. Nope, I had to bag up the dead cat, leave it for a friend to pick up later and have cremated when we were gone, and I got a lot of nasty looks from my wife for the first few days of the vacation…